Heavy-quark spin precession as a magnetic field chronometer
Abstract
The lifetime of the strong magnetic field generated in relativistic heavy-ion collisions remains one of the major open questions in the study of the quark--gluon plasma. We propose heavy-quark spin precession as a probe to quantify the magnetic field and its profile in such collisions. We investigate the Larmor evolution of polarized charm and bottom quarks propagating through an expanding quark--gluon plasma in the presence of the magnetic field. We show that realistic magnetic-field strengths and lifetimes generate measurable accumulated precession phases prior to hadronization, leading to characteristic charge-dependent polarization splittings between Λc+ and Λ̅c-, as well as between Λb0 and Λ̅b0, through the mixing of transverse and longitudinal polarization components. The predicted signals exhibit distinctive transverse-momentum and quark-mass dependence, providing complementary sensitivity to the magnetic-field lifetime in the charm and bottom sectors. Our results suggest heavy-flavor polarization, especially in the charm sector, as a quantitative probe for the space--time evolution of magnetic fields in relativistic heavy-ion collisions.
Related
- Quantum field theory treatment of the spin-flavor precession of Dirac neutrinos with diagonal magnetic moments
- Magnetic field-induced enhancement and quenching of Urca emission in quark matter
- Dense and Cold Magnetized Quark Matter: A Review of Magnetic-Field-Independent Regularization and the Medium Separation Scheme
- Photon production from gluon splitting and fusion induced by a magnetic field of arbitrary strength in relativistic heavy-ion collisions
- Equation of State of the Quark-Gluon Plasma in an External Magnetic Field to Fourth Order
BibTeX
@misc{sahu2026heavyquark,
title = {{Heavy-quark spin precession as a magnetic field chronometer}},
author = {Dushmanta Sahu and Captain R. Singh},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.22492},
eprint = {2609.22492},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.22492},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Heavy-quark spin precession as a magnetic field chronometer
AU - Dushmanta Sahu
AU - Captain R. Singh
PY - 2026
DA - 2026/09/18
PB - arXiv
DO - 10.48550/arxiv.2609.22492
UR - https://arxiv.org/abs/2609.22492
AB - The lifetime of the strong magnetic field generated in relativistic heavy-ion collisions remains one of the major open questions in the study of the quark--gluon plasma. We propose heavy-quark spin precession as a probe to quantify the magnetic field and its profile in such collisions. We investigate the Larmor evolution of polarized charm and bottom quarks propagating through an expanding quark--gluon plasma in the presence of the magnetic field. We show that realistic magnetic-field strengths and lifetimes generate measurable accumulated precession phases prior to hadronization, leading to characteristic charge-dependent polarization splittings between Λ_c^+ and Λ̅_c^-, as well as between Λ_b^0 and Λ̅_b^0, through the mixing of transverse and longitudinal polarization components. The predicted signals exhibit distinctive transverse-momentum and quark-mass dependence, providing complementary sensitivity to the magnetic-field lifetime in the charm and bottom sectors. Our results suggest heavy-flavor polarization, especially in the charm sector, as a quantitative probe for the space--time evolution of magnetic fields in relativistic heavy-ion collisions.
ER -